Biofuels: Challenges to the Transportation, Sale, and Use of Intermediate Ethanol Blends

摘要

U.S. transportation relies largely on oil for fuel. Biofuels can be an alternative to oil and are produced from renewable sources, like corn. In 2005, Congress created the Renewable Fuel Standard (RFS), which requires transportation fuel to contain 36 billion gallons of biofuels by 2022. The most common U.S. biofuel is ethanol, typically produced from corn in the Midwest, transported by rail, and blended with gasoline as E10 (10 percent ethanol). Use of intermediate blends, such as E15 (15 percent ethanol), would increase the amount of ethanol used in transportation fuel to meet the RFS. The Environmental Protection Agency (EPA) recently allowed E15 for use with certain automobiles. GAO was asked to examine (1) challenges, if any, to transporting additional ethanol to meet the RFS, (2) challenges, if any, to selling intermediate blends, and (3) studies on the effects of intermediate blends in automobiles and nonroad engines. GAO examined government, industry, and academic reports; interviewed Department of Energy (DOE), EPA, and other government and industry officials; and visited research centers.